<div id="menuTab">
<?php echo link_to('choice1','testjquery/choice1',array('class'=>'unselected',))?>
<?php echo link_to('choice2','testjquery/choice2',array('class'=>'unselected',))?>
<?php echo link_to('choice3','testjquery/choice3',array('class'=>'unselected',))?>
<?php echo link_to('choice4','testjquery/choice4',array('class'=>'unselected',))?>
</div>
<div id="testContent">
</div>
<script language="javascript">
  $(document).ready(
    function(){
      $("a").click(
        function(e){
          $("#menuTab > a").removeClass('selected').addClass('unselected');
          $(this).removeClass('unselected').addClass('selected');
          $.get(this.href,{},
            function(content){
              $("#testContent").html(content);
            }
          );
          e.preventDefault();
        }
      );
    }
  );
</script>